Electrode



J. K. FORSHEE.

ELECTRODE- APPLICATION FILED MAR. L8, 1920.

Patented Apr. 20, 1920.

UNITED STATES PATENT OFFICE.

JAMES K. FORSEEE, OF CHICAGO, ILLINOIS.

ELECTRODE.

To all whom it may concern Be it known that I, JAMES K. FoRsHnE,-a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Electrode, of which the following is a specification.

This invention is an electrode designed for use in connection with high-frequency or high-potential generators, although not limited in this particular.

One of the objects of the invention is to provide an electrode in which an electroconductive material and a dielectric material are so related that an electric discharge may be effected through the dielectric material. A further object is to provide an electrode which will perform all of the functions of the well-known vacuum electrode, and at the same time dispense with the maintaining of the vacuum heretofore considered necessary to the successful operation of devices of this character.

The invention will be hereinafter fully set forth and particularly pointedout in the claims.

In the accompanying drawing Figure 1 is a diagrammatic view illustrating the invention. Fig. 2 is a similar View illustrating a slight modification. Figs. 3 and 4 are longitudinal sectional views illustrating electrodes of common type constructed in accordance with the invention. Fig. 5 is a perspective view illustrating another type of electrode conformingito the invention.

' eferring to Fig. 1 of the drawing, the electrode is shown as constructed of an electro-conductive element or series of elements 10 and a dielectric element or series of elements 11, alternately arranged and preferably in close contact, the conductive elements being connected with any suitable source of electric power, such as the generator 12. The dielectric material is grounded in any suitable manner, as illustrated at 13. In practice, the dielectric and conductive elements are so related that when the electrode is connected with the generator and the dielectric material is grounded, the current breaks down the resistance of the dielectric material, and must pass through said material to the ground, the discharge thus effected possessing high therapeutic value, and also generating a very high degree of heat; the'temperetu e o whi w l ve y Specification of Letters Patent. Patented Apr, 20-, 1920, Application filed larch 18, 1920. Serial No.

with the intensit of the current ,and the character of the dielectric material. The inventlon is not limited to any particular electro-conductive material or to any particular dielectric material, because any electric conductor may be employed in connection with any dielectric material. Good results have been obtained with a metal conductor cooperating with a dielectric material, such as glass, fused silica, porcelain, and the like, but fused silica or glass is preferred because of their toughness and elasticity, and capability of resisting fusion under the temperatures generated.

In the form of the invention illustrated in Fig. 1, the electrode is shown'as consisting of alternately arranged sheets or plates of metal and dielectric material. In Fig. 2 is shown a slight modification in which the conductive material is in the form of a conductor 15 inclosed within a glass tube or between glass layers 16. The operation is the same as in the form illustrated in Fig. 1. In all of the forms the conductivematerial and the dielectric material should be preferably in close contact, free from air gaps, so that the electric discharge will be effected throughout the exposed surface of the dielectric material whenever the electrode is grounded.

In Figs. 3 and 4 are illustrated two common types of electrodes constructed in accordance with the invention. The form illustrated in Fig. 3 comprises a tubular stem 17 open at one end and provided at its other end with an enlarged hollow head 18 of any desired shape, similar to the usual vacuum-electrode. As shown, the electrode is constructed of a glass or fused silica body, and the interior surface thereof is coated with a conductive metal 19. The metal coating or lining may be applied in any manner, for instance, by electro-plating, and precipitation in connection'with afiinities, metalized paint, or metalizedglass, or in any other manner by which a permanent electro-conductive surface may be obtained.

As shown in Fig. 3, the metal coating extends to the open end of the stem 17, and electrical contact between said surface and a source of electrical energy may be provided in anysuitable or desired manner. Heretofore electrodes designed for use with high frequency currents and which employ a conductive element and a dielectric, have been subject to destruction by reason of the burning away of the conductive material. This is because there is not a sufficiently strong contact between the conductive element and the contact cap, or other device used for transmitting the current from its source. It

is therefore important to so connect the" conductive element with the contact member that said conductive element will be protected from the destructive action of the [0 current. One method of accomplishing this result is illustrated in Fig. 3. For instance, in some forms of the invention the open end of the stem 17 may be provided with a metal contact cap 20, having a wall extending thereinto into electric contact with the coating 19, said cap also having an exterior wall surrounding the end of the stem to provide for an electric contact with the usual electrode holder (not shown) The construcnot pass through the dielectric material, thus avoiding destructive heat at this point. It is preferred to construct said cap by electroplating and precipitation in connection with afiinities. By this is meant that the conductor cap must be of a metal which is sub: stantially identical with the metal forming the conductive element. For instance, if the coating 19 is of silverthe contact cap 20 should be of a metal very closely allied to silver. Otherwise the current will burn off the coating and the electrode will soon become useless. A copper contact cap, for example, may not be employed in connection with a silver coating and vice versa. The best results are obtained by constructing the contact cap of the same metal as that employed for the coating. It is believed that this method of providing for an electrical connection has never before been accomplished. In the form of the invention illustrated in Fig. 3, the electrode is connected with any source of electricity in a wellknown manner, and the current flowing through the cap 20, and metal coating 19, will be discharged through the body of dielectric material just as soon as the latter is grounded in any manner, whether by direct contact, through the atmosphere, or through an artificial ground such as the human body.

In lieu of constructing the electrode in the form of a hollow dielectric body with an internal conductive coating, the same may be in the form of a metal body, such as illustrated in Fig. 4, with a stem 21 and head 22, of any desired shape, said body being coated with the dielectric material 23, in any wellknown manner, the extremity of. the stem 60 being left uncoated, as shown at 24, to provide an electric connection with the source of current.

, Another form of electrode is illustrated in Fig. 5. In this form the dielectric body 2;;

65 is of approximately rectangular shape and tion is such that the entering current does provided with a longitudinal chamber 26, having conductor bars 27 attached to the walls thereof in suitable manner. The conductor bars are connected with a suitable source of electrical energy by wires 28, at- 70 tached to suitable contact members carried by said conductor bars. Grounded conductor plates 29 are arranged opposite to the conductor bars preferably in approxi mate juxtaposition, thus insuring concentration of the current to the grounded area. In

the drawing the ground plates 29 are shown slightly spaced from dielectric body 25, and

-it is to be understood that the distance between the two may be varied or they may be in contact, to meet various conditions. In operation, current flowing from the bars 27 will generate a very high temperature. An electrode of this type is capable of many uses for heating purposes.

The advantages of the invention will be readily apparent to those skilled in the art to which it appertains. It will be observed that the electrode above described is capable of effecting an electric discharge of high therapeutic value and that the same, by reason of the high temperature attainable, is capable of use for heating purposes, and when so used will be exceedingly economical in the use of electric current. It is also pos sible by the use of well-known apparatus to indefinitely maintain a fixed degree of temperature. It also has a high value when used to destroy insects and small vermin of all kinds. It will be particularly understood that it is not necessary to maintain a vacuum within the electrode and in fact it is preferred not to do so. In other words, the interior of a hollow electrode may be open to the atmosphere without in any manner impairing its efficiency. While the electrode has been described as designed to be used with high-frequency or high-potential generators, it is not limited in this particular, because it may also be used on static lnachines and to effect electric discharges irrespective of the character of the electromotive force or of its source.

I/Vhile several forms of the invention have been illustrated, it is not limited to any or either of these forms, as it will be clearly understood that the invention is, within itself, not of design nature. Therefore it is not desired to be limited to the precise constructions as set forth, but to comprehend such modifications as come within the scope of the appended claims.

This application is a continuation in part of an application filed March 12, 1919, Serial Number 282,058.

Having thus explained the nature of the invention and described an operative manner of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or 130 tensive area of, the dielectric elementyand in such relation thereto that any grounding ofthe current must always take place through the dielectric material, whereby heat 15 generated, said dielectric element being of a material capable of resisting fusion by the said heat, and a single means whereby said electrode may be connectedv with a source of electrical energy, said means'being constructed to prevent injurious heating of the electrode at the point wherethe current enters it. I V

2. An electrode of the characterdescribed comprising a dielectric element, a conductor element having a substantial portion of its area in contact with a coextensive area of the dielectric element and in such relation thereto that any grounding of the current must always take place through the dielectric material, whereby heat is generated, said dielectric element being of a material capable of resisting fusion bv the said heat, and a single contact member so connected with said conductor element as to avoid passing the entering current through" the dielectric material, whereby dangerous heating at the point where the current enters the electrode is prevented.

3. An electrode of the character described comprising a hollow body 'open to the atmosphere and formed of an internal electroconductive element and an external dielectric element, said electro-conductive element having a single means for connection with a source of electrical energy, said elements being so related that any grounding of the current must take place through the dielectric element.

4. An electrode of the character described comprising a hollow body of dielectric material having a substantial portion of its interior coated with conductive material, said materials being so related that any grounding of the current must always take place through the delectric material whereby heat is generated, said dielectric element being of a material capable of resisting fusion by the said-heat, and a single means whereby said coating may be connected with a source of electrical energy, said means being constructed to prevent injurious heating of the electrode at the point where the current enters it.

5. An electrode of the character described comprising a hollow body of dielectric material open to the atmosphere and provided with an internal coating of conductive material having a single means for connection with a source of electrical energy, said materials being so related that any grounding of the current must take place through the dielectric material, whereby heat is generated in the dielectric material by the resistance thereof. 6. An electrode of the character described comprising a hollow stem formed of dielectric material and closed at one end and open at the other, and a coating of conductive material on the interior of said stem provided with a single means for connection with a source of electrical energy, said materials being so related that any grounding of the current must take place through the dielectric material, whereby heat is generated in the latter by the resistance thereof. 7. An electrode of the character described comprising a stem open at one end and provided' at the other end with a hollow enlargement, said stem and enlargement being constructed of dielectric material, and a coating of conductive material on the inner surface of the stem and the enlargement,

ance thereof.

8. An electrode of the character described comprising a dielectric body formed with a stem open at one end and closed at the other end by an enlarged head, the interior of said body being lined with conductive material and provided with a single means for connection with a source of electrical energy, said materials being in such close contact that. any grounding of the current must take place through the dielectric body, whereby heat is generated in the latter by the resistance thereof.

9. An electrode of the character described comprising a body of dielectric material formed with a stem open at one end and closed at the other, the interior of said body being lined with conductive material and a contact cap on the open end of said stem and in contact with said conductive material, the dielectric and conductive materials being so related that any grounding of the current must take place through the dielectric material, whereby heat is generated in the latter by the resistance thereof.

10. An electrode of the character described comprising a body of dielectric material having a substantial portion of one surface provided with a precipitated metal coating coextensive area of the dielectric element and so related thereto that any grounding of the current must take place through the dielectric material, whereby heat is gener ated, said dielectric element being of a material capable of resisting fusion by the said heat, and a single conductor member of a nature so related to the conductive element that it will protect the latter from the destructive action of the current.

12. An electrode of the character described comprising a body of dielectric material inclosing a conductive element, a substantial portion ofthe area of said conductive element being in contact with a coextensive area of the dielectric element and so related thereto that any grounding of the current must take place through the dielectric element whereby heat is generated, said dielectric element being of a material capable of resisting fusion by the said heat, and a single metalized or electroplated contact member having a union with the conductive element, said contact element being of a material so related to the conductive element that it will protect the latter from the destructive action of the current.

13. An electrode of the character described comprising a body of dielectric material inclosing a conductive element, a substantial portion of the area of said condnctive element being in contact with a coextensive area of the dielectric element and so related thereto that any grounding of the current must always take place through the dielectric material, whereby heat is generated, said dielectric element being of a material capable of resisting fusion by the said heat. and a single contact cap inclosing one end of said electrode and having a union with the conductive element, said cap being of a material .so related to the conductive element that it will protect the latter from the destructive action of the current.

14. An electrode of the character described comprising abody of dielectric material provided with a precipitated metal coating of substantial area, so related thereto that any grounding of the current must pass through the dielectric body, whereby heat is generated, said dielectric element being of a material capable of resisting fusion by the said heat, and a single precipitated metal contact member connected with said coating, said contact memher being of a material so related to the coating that it will protect the latter from the destructive action of the current.

15. An electrode of the character described comprising a body of dielectric material inclosing a conductive element, a

substantial portion of the area of said conductive element being in contact with a coextensive area of the dielectric element and so related thereto that any grounding of the current must take lace through the dielectric material, where y heat is generated, said dielectric element being of a material capable of resisting fusion by the said heat, and a single contact member so connected with said conductive element as to prevent injurious heating of the electrode at the point where the current enters it, said contact member bein of a material so related to the conductive e ement that it will protect the latter from the destructure action of the current.

In testimony whereof I have hereunto set my hand.

JAMES K. Fons EE. 

